The Reds are left frustrated as QPR hit back late on to steal a point at Oakwell.
Barnsley were denied all three points in the Sky Bet Championship clash under the Oakwell lights as the visitors struck with three minutes remaining, Luke Freeman's strike cancelling out Harvey Barnes' first half wonder-goal.
Paul Heckingbottom made two changes from the weekend's visit to Wolves, with Zeki Fryers making his home debut, replacing Matty Pearson and Ike Ugbo returned to the starting line-up replacing Tom Bradshaw.
It was a very quiet first half with few clear-cut opportunities created by either side but with the Reds dominating possession.
20 minutes into the game and the first real piece of notable action arrived with the Reds taking the lead...
Some good work down the left by George Moncur and Fryers saw a ball fall into the path of Barnes who hit a sweet right-footed curler from the left edge of the box, just over 20 yards out and the first time effort flew into the top corner of the Rangers net with Alex Smithies well beaten.
The goal brought the Reds to life and Adam Jackson went close to doubling the lead but his looping header dropped agonisingly wide of the post.
HALF TIME: Barnsley 1-0 QPR
There was a change for both sides at the break with Rangers bringing on Conor Washington in place of Bright Osayi-Samuel and Hecky replaced goal-scorer Barnes with Bradshaw as Barnsley now set up in a 4-4-2 formation.
It was a livelier second half with Jake Bidwell going close for the away side as his right-foot volley swerved just over the bar on 51 minutes.
Ugbo saw a fierce drive repelled by the visiting 'keeper soon afterwards as the game became stretched a little.
Former Barnsley man Josh Scowen put a header just over the crossbar on 64 minutes.
With just over 20 minutes remaining, the ball fell to Adam Hammill invitingly, 30 yards out and the winger lifted a powerful, dipping volley towards goal which had Smithies scrambling and tipping over for a Reds corner.
George Moncur was withdrawn on 70 minutes, replaced by Cameron McGeehan.
With 10 minutes left to play Hecky made a final change by putting Ryan Hedges on for Brad Potts.
And then the sucker punch..
87 minutes into the game and with the Reds now defending their lead, a loose ball was picked up by Freeman and he chanced his arm from 25 yards out, beating Adam Davies with a powerful effort.
It was a sickening blow once again late on, as Barnsley had to settle for a point.
FULL TIME: Barnsley 1-1 QPR
Reds XI: Davies, McCarthy, Jackson, Lindsay, Fryers, Williams, Moncur (McGeehan '70), Potts (Hedges '80), Barnes (Bradshaw '46), Ugbo, Hammill.
Unused: Townsend, MacDonald, Thiam, Pearson.
Att: 10,920 (335 away)